Bonn Agreement of 1931

Ecumenical Agreement between Anglicans and the Old Catholic Churches, which incorporates these three principles:

1. Each Communion recognizes the catholicity and independence of the other and maintains its own.
2. Each Communion agrees to admit members of the other Communion to participate in the Sacraments.
3. Full Communion does not require from either Communion the acceptance of all doctrinal opinion, sacramental devotion or liturgical practice characteristic of the other, but implies that each believes the other to hold all the essentials of the Christian faith.

Read about the Society of St. Willibrord here.